[Trunk] Unable to join the group

[DBR (OpenERP)]

Hello,

Tested with today's Latest trunk DB on Runbt.
Go to Runbt and click on connect.
There is a screen showing the project details without login.
Go to portal > About Us > News or jobs
able to see the list of groups ...
Try to join any one of them...

Expected:
Asking for login/signup because you want to join that group

Result:
Traceback (most recent call last):
  File "/home/odoo/runbot/static/openerp-dev-trunk-15978/server/openerp/addons/web/http.py", line 308, in dispatch
    response["result"] = self._call_function(**self.params)
  File "/home/odoo/runbot/static/openerp-dev-trunk-15978/server/openerp/addons/web/http.py", line 184, in _call_function
    return self.func(*args, **kwargs)
  File "/home/odoo/runbot/static/openerp-dev-trunk-15978/server/openerp/addons/web/http.py", line 1043, in nfunc
    return func(*args, **kwargs)
  File "/home/odoo/runbot/static/openerp-dev-trunk-15978/server/openerp/addons/web/controllers/main.py", line 1094, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "/home/odoo/runbot/static/openerp-dev-trunk-15978/server/openerp/addons/web/controllers/main.py", line 1086, in _call_kw
    return getattr(request.session.model(model), method)(*args, **kwargs)
  File "/home/odoo/runbot/static/openerp-dev-trunk-15978/server/openerp/addons/web/http.py", line 573, in proxy
    result = meth(cr, request.uid, *args, **kw)
  File "/home/odoo/runbot/static/openerp-dev-trunk-15978/server/openerp/addons/mail/mail_thread.py", line 1439, in message_subscribe_users
    return self.message_subscribe(cr, uid, ids, partner_ids, subtype_ids=subtype_ids, context=context)
  File "/home/odoo/runbot/static/openerp-dev-trunk-15978/server/openerp/addons/mail/mail_thread.py", line 1456, in message_subscribe
    existing_pids = set([f.id for f in record.message_follower_ids
  File "/home/odoo/runbot/static/openerp-dev-trunk-15978/server/openerp/osv/orm.py", line 484, in __getattr__
    return self[name]
  File "/home/odoo/runbot/static/openerp-dev-trunk-15978/server/openerp/osv/orm.py", line 473, in __getitem__
    self._data[result_line['id']].update(new_data)
AttributeError: Got KeyError(59,) while trying to get attribute message_follower_ids on a mail.group record.